U.S. patent application number 11/259122 was filed with the patent office on 2006-05-04 for camera system.
This patent application is currently assigned to FUJI PHOTO FILM, CO., LTD.. Invention is credited to Hirofumi Horii, Kazunori Suemoto.
Application Number | 20060093343 11/259122 |
Document ID | / |
Family ID | 36262034 |
Filed Date | 2006-05-04 |
United States Patent
Application |
20060093343 |
Kind Code |
A1 |
Horii; Hirofumi ; et
al. |
May 4, 2006 |
Camera system
Abstract
A camera system comprises: a camera head comprising an imaging
optical system through which a subject light passes, an imaging
device that obtains image data representative of the subject light
formed through the imaging optical system, an information
transmission section that transmits imaging information necessary
for obtaining a degree of strictness to be determined in an
in-focus on the imaging device, and an image transmission section
that transmits the image data obtained by the imaging device; and a
camera main frame comprising a connection section on which the
camera head is detachably mounted, an image receiving section that
receives image data; an image processing section that applies a
predetermined image processing to the image data received by the
image receiving section, and an information receiving section that
receives the imaging information.
Inventors: |
Horii; Hirofumi; (Asaka,
JP) ; Suemoto; Kazunori; (Asaka, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
FUJI PHOTO FILM, CO., LTD.
|
Family ID: |
36262034 |
Appl. No.: |
11/259122 |
Filed: |
October 27, 2005 |
Current U.S.
Class: |
396/91 ;
348/E5.025; 348/E5.045 |
Current CPC
Class: |
G03B 17/44 20130101;
H04N 5/2254 20130101; G03B 17/14 20130101; H04N 5/232123
20180801 |
Class at
Publication: |
396/091 |
International
Class: |
G03B 3/00 20060101
G03B003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 29, 2004 |
JP |
2004-315927 |
Claims
1. A camera system comprising: a camera head comprising an imaging
optical system through which a subject light passes, an imaging
device that obtains image data representative of the subject light
formed through the imaging optical system, an information
transmission section that transmits imaging information necessary
for obtaining a degree of strictness to be determined in an
in-focus on the imaging device, and an image transmission section
that transmits the image data obtained by the imaging device; and a
camera main frame comprising a connection section on which the
camera head is detachably mounted, an image receiving section that
receives image data; an image processing section that applies a
predetermined image processing to the image data received by the
image receiving section, and an information receiving section that
receives the imaging information.
2. A camera system according to claim 1, wherein the information
transmission section transmits, as the imaging information, at
least one of a subject distance up to the subject, a focal length
of an imaging optical system, a light-condensing ability, size and
number of pixels of the imaging device, and pixel pitch of the
imaging device.
3. A camera system according to claim 1, wherein the camera system
further comprises: an operating section that computes a depth of
field and/or an in-focus range in accordance with the imaging
information, belonging to the camera head and/or the camera main
frame; and a display section that displays the depth of field
and/or the in-focus range, which are computed in the operating
section, belonging to the camera head and/or the camera main
frame.
4. A camera system according to claim 1, wherein the camera system
further comprises: an operating section that computes a depth of
field and/or an in-focus range in accordance with the imaging
information and a subject distance to be entered, belonging to the
camera head and/or the camera main frame; and a display section
that displays the depth of field and/or the in-focus range, which
are computed in the operating section, belonging to the camera head
and/or the camera main frame.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a camera system comprising:
a camera head that is loaded with an image taking optical system
for forming a subject light and an imaging device that reads the
subject light to generate image data; and a camera main frame on
which the camera head is detachably mounted, the camera main frame
applying a predetermined image processing to the image data.
[0003] 2. Description of the Related Art
[0004] Hitherto, there is known an interchangeable lens digital
camera in which an interchangeable image taking lens is mounted on
a camera main frame incorporating an imaging device. According to
the interchangeable lens digital camera, a subject light formed by
an image taking lens is fed to the imaging device provided on the
camera main frame to create photographic image data. Accordingly,
it is possible to reuse an interchangeable lens, which is used in a
film type of single-lens reflex camera for recording a photographic
image on a silver halide film.
[0005] However, for example, in the event that a large scale of
image taking lens, which is excellent in an optical property, is
mounted on a camera main body that incorporates therein a small
type of imaging device that is low in resolution, while the image
taking lens forms the subject light with great accuracy, the
imaging device cannot read the subject light with great accuracy.
This involves a problem that it is difficult to make the best use
of a property of the image taking lens.
[0006] In this respect, Japanese Patent Application Laid Open
Gazette TokuKai Hei. 8-172561 discloses an interchangeable head
digital camera in which a camera head incorporating therein an
image taking lens and an imaging device is mounted on a camera main
frame. According to the technology disclosed in Japanese Patent
Application Laid Open Gazette TokuKai Hei. 8-172561, a provision of
CCD suitable for a size of the image taking lens and an optical
property in the camera head beforehand makes it possible to obtain
a high picture quality of photographic image through performing
photography making the best use of the image taking lens.
[0007] By the way, in the field of a digital camera, the 35 mm
corresponding focal length (a focal length on the 35 mm film), a
depth of field, and an in-focus range are computed in accordance
with a size of an imaging device. A user's confirmation of the 35
mm corresponding focal length makes it possible to recognize a view
angle of photography in conversion into a familiar film type of
camera. Further, a user's confirmation of the depth of field, and
the in-focus range makes it possible to recognize as to what
distance range of the subject from the camera can be focused, so
that the user can perform photography through focusing to a
plurality of subjects mutually different from one another in
distance.
[0008] However, according to the interchangeable head digital
camera disclosed in Japanese Patent Application Laid Open Gazette
TokuKai Hei. 8-172561, the image taking lens and the imaging device
are provided on the camera head in form of a set. Accordingly, when
the taking lens is interchanged, the imaging device is together
interchanged. Thus, this involves such a problem that a size of the
imaging device is greatly changed, and as result, it is impossible
to compute the depth of field and the in-focus range.
SUMMARY OF THE INVENTION
[0009] In view of the foregoing, it is an object of the present
invention to provide a camera system comprising: a camera head that
is loaded with an image taking optical system for forming a subject
light and an imaging device that reads the subject light to
generate image data; and a camera main frame on which the camera
head is detachably mounted, wherein the camera system is capable of
computing the depth of field and the in-focus range, even if the
camera head is interchanged.
[0010] To achieve the above-mentioned objects, the present
invention provides a camera system comprising:
[0011] a camera head comprising an imaging optical system through
which a subject light passes, an imaging device that obtains image
data representative of the subject light formed through the imaging
optical system, an information transmission section that transmits
imaging information necessary for obtaining a degree of strictness
to be determined in an in-focus on the imaging device, and an image
transmission section that transmits the image data obtained by the
imaging device; and
[0012] a camera main frame comprising a connection section on which
the camera head is detachably mounted, an image receiving section
that receives image data; an image processing section that applies
a predetermined image processing to the image data received by the
image receiving section, and an information receiving section that
receives the imaging information.
[0013] According to the camera system of the present invention, the
camera head transmits the imaging information such as size and
number of pixels of the imaging device, and pixel pitch of the
imaging device to the camera main frame. For example, the camera
main frame computes a degree of strictness to be determined in an
in-focus on the imaging device in accordance with the imaging
information, so that a user can perform photography through
regulation of a distance up to the subject in accordance with the
computed degree.
[0014] In the camera system according to the present invention as
mentioned above, it is preferable that the information transmission
section transmits, as the imaging information, at least one of a
subject distance up to the subject, a focal length of an imaging
optical system, a light-condensing ability, size and number of
pixels of the imaging device, and pixel pitch of the imaging
device.
[0015] According to the camera system of the present invention as
mentioned above, it is possible to compute a depth of field and an
in-focus range, which are representative of the distance range
focusing on the subject, using the subject distance, the focal
length of the imaging optical system, the light-condensing ability,
size and number of pixels of the imaging device, and pixel pitch of
the imaging device.
[0016] In the camera system according to the present invention as
mentioned above, it is preferable that the camera system further
comprises:
[0017] an operating section that computes a depth of field and/or
an in-focus range in accordance with the imaging information,
belonging to the camera head and/or the camera main frame; and
[0018] a display section that displays the depth of field and/or
the in-focus range, which are computed in the operating section,
belonging to the camera head and/or the camera main frame.
[0019] Display of the depth of field and/or the in-focus range on
the display section makes it possible for a user to recognize a
permissible range in-focus for the subject. Thus, according to the
camera system of the present invention, it is possible for the user
to adjust the distance up to the subject before the photography and
to obtain a photograph focussing on the subject.
[0020] In the camera system according to the present invention as
mentioned above, it is preferable that the camera system further
comprises:
[0021] an operating section that computes a depth of field and/or
an in-focus range in accordance with the imaging information and a
subject distance to be entered, belonging to the camera head and/or
the camera main frame; and
[0022] a display section that displays the depth of field and/or
the in-focus range, which are computed in the operating section,
belonging to the camera head and/or the camera main frame.
[0023] An input of the subject distance by a user makes it possible
to compute the depth of field and/or the in-focus range, even in
the event that the photography is carried out in the dark place and
thus the focusing unit cannot operate properly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is an exploded view of a camera system according to
an embodiment of the present invention.
[0025] FIG. 2 is a side view of a camera system 1 shown in FIG.
1.
[0026] FIG. 3 is an internal structural view of the camera system 1
shown in FIG. 1.
[0027] FIG. 4 is a flowchart useful for understanding a series of
processing up to displaying of information on an information
display section.
[0028] FIG. 5 is a flowchart useful for understanding a series of
processing up to displaying of information on an information
display section.
[0029] FIG. 6 is a side view of a camera head 1.sub.--a' in a
camera system according to a second embodiment.
[0030] FIG. 7 is an internal structural view of the camera system 2
according to the second embodiment.
[0031] FIG. 8 is a flowchart useful for understanding a series of
processing up to displaying of information on an information
display section 1051a of the camera head of the camera head
1.sub.--a'.
[0032] FIG. 9 is an internal structural view of the camera system 3
according to the present embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] Embodiments of the present invention will be described with
reference to the accompanying drawings.
[0034] FIG. 1 is an exploded view of a camera system according to
an embodiment of the present invention.
[0035] FIG. 1 shows a camera system 1 having a plurality of sorts
of camera heads 1.sub.--a, 2.sub.--a, . . . , n_a each comprising
an image taking lens and a CCD. In the camera system 1, any one of
the pluralities of sorts of camera heads 1.sub.--a, 2.sub.--a, . .
. , n_a is selectively used. In the following explanation, it is
assumed that the camera head 1.sub.--a is typically selected.
[0036] In the camera system 1, the camera head 1.sub.--a, which is
loaded with CCD 12a (not illustrated in FIG. 1, and refer to FIG.
3) and an image taking optical system 11a (not illustrated in FIG.
1, and refer to FIG. 3), is detachably mounted on a camera main
frame 1.sub.--b that is provided with an image display section
1050b (not illustrated in FIG. 1, and refer to FIG. 3) for
displaying a photographic image and a menu image. The camera main
frame 1.sub.--b corresponds to an example of the camera main frame
referred to in the present invention. The camera heads 1.sub.--a,
2.sub.--a, . . . , n_a correspond to an example of the camera head
referred to in the present invention.
[0037] The camera head 1.sub.--a is provided with a head mounting
connector 10a. The head mount connector 10a is detachably engaged
with a main frame mount 10b provided in front of the camera main
frame 1.sub.--b. The main frame mount 10b corresponds to an example
of the connection section referred to in the present invention.
[0038] FIG. 2 is a side view of a camera system 1 shown in FIG.
1.
[0039] The camera head 1.sub.--a is provided with an operating
section 2 for control of a movement of a zoom lens and focus lens.
At a side of the camera head 1.sub.--a, there is described CCD
information 3 such as a size of the CCD 12a (not illustrated in
FIG. 2, and refer to FIG. 3) incorporated into the camera head
1.sub.--a, and the number of pixels. At a side of the camera main
frame 1.sub.--b, there is provided an information display section
1051b for displaying character information and the like, which is
smaller than the image display section 1050b (not illustrated in
FIGS. 1 and 2, and refer to FIG. 3) provided on the back. The
information display section 1051b corresponds to an example of the
display section referred to in the present invention.
[0040] FIG. 3 is an internal structural view of the camera system 1
shown in FIG. 1.
[0041] First, there will be explained the structure of the camera
head 1.sub.--a.
[0042] The camera head 1.sub.--a comprises: an image taking optical
system 11a that is provided with various sorts of lenses such as a
focus lens and a zoom lens, and a motor for driving those lenses; a
stop/focus/zoom control section 17a that controls the motor of the
image taking optical system 11a to control a diameter of a stop of
the image taking optical system 11a and positions of the focus lens
and the zoom lens; a CCD 12a for receiving a subject light formed
through the image taking optical system 11a to create a subject
signal representative of the subject light; an analog signal
processing section 13a for performing an amplification of the
subject signal and a gain regulation; an A/D conversion section 14a
for converting the subject signal of an analog signal to image data
of digital; a TG (timing generator) 18a for generating a timing
signal to the CCD 12a, the analog signal processing section 13a and
the A/D conversion section 14a; a head CPU 19a for controlling each
element of the camera head 1.sub.--a and for computing lens
positions of the focus lens and the zoom lens; a system memory 190a
that stores a program indicative of a processing procedure
concerning the AE detection and the AF detection; and a
non-volatile storage 191a that stores therein head parameters such
as the number of pixels of the CCD 12a and the aperture value. The
image taking optical system 11a corresponds to an example of the
image taking optical system referred to in the present invention.
The CCD 12a corresponds to an example of the imaging device
referred to in the present invention.
[0043] The camera head 1.sub.--a further comprises: an information
communication section 151a for communicating information such as
head parameters between the camera head 1.sub.--a and the camera
main frame 1.sub.--b; and an image transmission section 150a for
transmitting photographic image data in which the subject light is
read by the camera main frame 1.sub.--b. The information
communication section 151a corresponds to an example of the
information communication section referred to in the present
invention.
[0044] In the camera head 1.sub.--a, when the CCD 12a receives the
subject light, the camera head 1.sub.--a creates three types of
image data such as low resolution data for through image use as to
the subject image now in the photographic view angle, which is to
be displayed on the image display section 1050b of the camera main
frame 1.sub.--b, still picture image data representative of a still
picture image when a release button 13b is depressed, and dynamic
picture image data representative of a dynamic picture image. The
low resolution data is low in resolution and is a temporal data.
Thus the image transmission section 150a transmits the low
resolution data to the camera main frame 1.sub.--b and also to an
integration circuit 16a.
[0045] The camera head 1.sub.--a still further comprises: a power
source control section 100a for controlling a power to be supplied
to the integration circuit 16a for detecting luminance (AE
detection) of the subject and contrast (AF detection) of the
subject in accordance with the low resolution data, the camera head
1.sub.--a, and the various elements of the camera head 1.sub.--a,
and a DC/DC converter 101a.
[0046] Next, there will be explained the camera main frame
1.sub.--b.
[0047] The camera main frame 1.sub.--b comprises: a focusing unit
171b for computing a subject distance up to the subject in
accordance with the low resolution data transmitted from the camera
head 1.sub.--a; a main frame CPU 100b for controlling various
elements of the camera system 1 and also for computing depth of
field in accordance with the subject distance and the head
parameters; a system memory 101b that stores a program; an
information communication section 151b for communicating
information between the camera head 1.sub.--a and the camera main
frame 1.sub.--b; an image receiving section 150b for receiving
image data transmitted from the camera head 1.sub.--a; a
non-volatile storage 102b for storing head parameters received by
the information communication section 151b; a timer 10b for timer
photography; a calendar timer section 111b for displaying a
calendar timer on the image display section 1050b; a USB driver
131b to which a personal computer and the like are connected via a
USB connector 130b; a flash emitting section 121b for emitting
flash through a flash emitting window provided on the camera main
frame 1.sub.--b; a flash emitting control section 120b for
controlling an amount of light emission by the flash emitting
section 121b; a switch/LED 132B that is controlled by the main
frame CPU 100b through an I/O 133b; a power source SW 14b for
turning on and off a power source of the camera system 1; a battery
142b for supplying an electric power to the camera system 1; a
power source control section 140b for controlling an electric power
to be supplied from battery 142b to the respective elements of the
camera main frame 1.sub.--b; a DC/DC converter 146b for regulating
the electric power; a latch 143b that maintains and supplies the
electric power via an I/O 141b to the camera head 1.sub.--a; an
image processing section 109b for applying various sorts of
processing such as compression processing to the image data
received by the image receiving section 150b; a display control
section 105b for controlling a display on the image display section
1050b and the information display section 1051b; the image display
section 1050b on which various menu screens and through images
based on the low resolution data are displayed; the information
display section 1051b on which the main frame CPU 100 and depth of
field to be computed are displayed; and a memory card slot 107b on
which there may be mounted a memory card 108b in which image data
created at the time of photography is compressed by the image
processing section 109b, and the compressed image data is recorded
via a card I/F 106b on the memory card 108b. The image receiving
section 150b corresponds to an example of the image receiving
section referred to in the present invention. The information
communication section 151b corresponds to an example of the
information communication section referred to in the present
invention. The image processing section 109b corresponds to an
example of the image processing section referred to in the present
invention. The main frame CPU 100 corresponds to an example of the
operating section referred to in the present invention.
[0048] The camera system 1 comprises the camera head 1.sub.--a and
the camera main frame 1.sub.--b and is constructed in such a manner
that the head mounting connector 10a is detachably mounted on the
camera main frame mount 10b. Between the camera head 1.sub.--a and
the camera main frame 1.sub.--b there is performed a communication
via electric contacts provided on the head mounting connector 10a
and the camera main frame mount 10b.
[0049] In the camera system 1 according to the present embodiment,
the information display section 1051b of the camera main frame
1.sub.--b displays a depth of field and an in-focus range.
[0050] FIG. 4 and FIG. 5 are each a flowchart useful for
understanding a series of processing up to displaying of the depth
of field and the in-focus range on the information display section
1051b.
[0051] The non-volatile storage 191a of the camera head 1.sub.--a
beforehand stores, as head parameters, a size of the CCD 12a, the
number of pixels of the CCD 12a, F-value of the image taking
optical system 11a, and the focal length.
[0052] When a user turns on the power source SW 14b, an electric
power is supplied from the battery 142b to the camera system 1
(step S11 of FIG. 4). When the electric power is supplied to the
camera head 1.sub.--a, the head CPU 19a is activated (step S12 of
FIG. 4).
[0053] First, the head CPU 19a obtains the head parameters stored
in the non-volatile storage 191a of the camera head 1.sub.--a (step
S13 of FIG. 4).
[0054] Next, the obtained head parameters are transmitted via the
information communication section 151a, the mount contact, and the
information communication section 151b to the main frame CPU 100b
(step S14 of FIG. 4).
[0055] The head parameters, which are fed to the main frame CPU
100b, are stored in the non-volatile storage 102b of the main frame
CPU 100b. Of the head parameters, the CCD information 3 shown in
FIG. 2 is fed to the display control section 105b and is displayed
on the information display section 1051b (step S15 of FIG. 4).
[0056] A user can compute 35 mm corresponding focal length in
accordance with the CCD information 3 displayed on the information
display section 1051b, so that the user can confirm the
photographic view angle where it is converted into the film camera
which is familiar to the user.
[0057] When the user uses a handler (not illustrated) provided on
the camera main frame 1.sub.--b to set up the image data size, a
photographic mode, and needs of the flash, a computation of the
depth of field is started (step S21 of FIG. 5).
[0058] The main frame CPU 100b sends a transmission instruction for
low resolution data via the information communication section 151b
and the information communication section 151a to the camera head
1.sub.--a.
[0059] In the camera head 1.sub.--a, the focus lens, which is
included in the image taking optical system, is driven in the
optical axis direction in accordance with an instruction from the
head CPU 10a, and the CCD 12a roughly reads the subject light in
the timing from the TG 18a, so that the low resolution data is
generated via the analog signal processing section 13a and the A/D
conversion section 14a. The low resolution data is transmitted to
the integration circuit 16a so as to be subjected to the AF
processing and the AE processing. The generated low resolution data
is also transmitted via the information communication section 151a
and the information communication section 151b to the main frame
CPU 100b and the focusing unit 171b (step S25 of FIG. 5). The
focusing unit 171b computes the subject distance in accordance with
the low resolution data (step S26 of FIG. 5). The thus computed
subject distance is transmitted to the main frame CPU 100b (step
S27 of FIG. 5).
[0060] In the main frame CPU 100b, the head parameters, which are
stored in the non-volatile storage 102b of the camera main frame
1.sub.--b, are obtained (step S22 of FIG. 5). At that time, in the
main frame CPU 100b, there are obtained information related to the
image taking optical system 11a such as F-value of the image taking
optical system 11a and focal length (step S23 of FIG. 5), and
information related to the CCD12a such as a size of the CCD12a and
the number of pixels (step S24 of FIG. 5). The main frame CPU 100b
computes a depth of field and the in-focus range in accordance with
the subject distance transmitted from the focusing unit 171b and
the head parameters (step S28 of FIG. 5). The depth of field is
determined in accordance with the following formula.
[0061] The depth of
field=d.times.F.times.a/(f.sup.2+d.times.f.times.a)
[0062] where d: a permissible circle of confusion (it is decided by
the pitch of the CCD 12a, and is computed from the size of the CCD
12a and the number of pixels), F: F-value, a: a subject distance,
f: focal length
[0063] A result of the computation is transmitted to the control
section 105b and is displayed on the image display section 1050b of
the camera main frame 1.sub.--b. For example, in case of "CCD size:
1/1.7 inch, 6M pixels, F2.8, subject distance: 2.0 m, focal length:
28 mm, and APS size", there is displayed information such as
"in-focus range: 2.3 m to 4.2 m, and depth of field: 2.4".
[0064] In this manner, a display of the in-focus range and the
depth of field on the information display section 1051b makes it
possible for a user to, for example, move lengths of a plurality of
subjects to the in-focus range to perform photography. This feature
makes it possible to obtain a photographic image free from out of
focus.
[0065] Next, there will be explained the second embodiment. A
camera system of the second embodiment is substantially same as the
camera system 1 of the first embodiment in the structure. Thus, in
the following figures, the same parts are denoted by the same
reference numbers as those of FIG. 1 to FIG. 5, and the redundant
explanation will be omitted, and only the different points will be
explained.
[0066] FIG. 6 is a side view of a camera head 1.sub.--a' in a
camera system according to the second embodiment. FIG. 7 is an
internal structural view of the camera system 2. according to the
second embodiment.
[0067] As shown in FIG. 6, on the side of the camera head
1.sub.--a' there is provided an information display section 1051a
for displaying a depth of field and the like. The information
display section 1051a corresponds to the example of the information
display section referred to in the present invention.
[0068] As shown in FIG. 7, according to the camera system 2 of the
second embodiment, the camera main frame 1.sub.--b is not provided
with the information display section 1051b. The camera head
1.sub.--a' is provided with an information display section 1051a
and a display control section 105a for controlling a display of
information to the information display section 1051a.
[0069] FIG. 8 is a flowchart useful for understanding a series of
processing up to displaying of information on an information
display section 1051a of the camera head of the camera head
1.sub.--a'.
[0070] In a similar fashion to that of the step S21 of FIG. 5, when
the user sets up the image data size, a photographic mode, and
needs of the flash, a computation of the depth of field is started
(step S31 of FIG. 8).
[0071] According to the present embodiment, the head CPU 19a of the
camera head 1.sub.--a' instructs respective elements of the camera
head 1.sub.--a' to generate the low-resolution data. The
low-resolution data thus generated is transmitted via the image
transmission section 150a and the image receiving section 150b to
the main frame CPU 100b and the focusing unit 171b (step S34 of
FIG. 8). The focusing unit 171b computes the subject distance in
accordance with the low resolution data (step S35 of FIG. 8). The
computed subject distance is transmitted via the information
communication section 151b and the information communication
section 151a to the head CPU 19a.
[0072] The head CPU 19a obtains the head parameters stored in the
non-volatile storage 191a of the camera head 1.sub.--a' (steps S32
and S33 of FIG. 8).
[0073] Further, the head CPU 19a computes a depth of field and an
in-focus range in accordance with the head parameters and the
subject distance transmitted from the focusing unit 171b (step S37
of FIG. 8).
[0074] The computed result is transmitted to the display control
section 105a of the camera head 1.sub.--a' so as to be displayed on
the information display section 1051a.
[0075] In this manner, it is acceptable that the information such
as the depth of field and the in-focus range are displayed on the
information display section 1051a of the camera head 1.sub.--a',
but not information display section 1051b of the camera main frame
1.sub.--b. In this case, in order to reduce the time for data
communication, it is preferable that the head CPU 19a of the camera
head 1.sub.--a', but not the main frame CPU 100b of the camera main
frame 1.sub.--b computes the depth of field and the in-focus
range.
[0076] Next, there will be explained a third embodiment. A camera
system of the third embodiment is substantially same as the camera
systems of the first embodiment and the second embodiment in the
structure. Thus, in the following figures, the same parts are
denoted by the same reference numbers as those of FIG. 1 to FIG. 8,
and the redundant explanation will be omitted, and only the
different points will be explained.
[0077] FIG. 9 is an internal structural view of the camera system 3
according to the present embodiment.
[0078] According to the camera system 3 as shown in FIG. 9, a
subject distance input unit 172b replaces the focusing unit 171b.
According to the camera system 3, the user uses the subject
distance input unit 172b to input a distance up to the subject. The
entered subject distance is transmitted to the main frame CPU 100b
so as to be used for computation of a depth of field and the
like.
[0079] In this manner, the user's input of the subject distance
makes it possible to compute a depth of field, even if the user
perform photography at the dark place and cannot compute the depth
of field with a focusing unit.
[0080] According to the present embodiments, there is explained the
camera system provided with the CCD as an imaging device. However,
it is acceptable that the imaging device referred to in the present
invention is the MOS and the like.
[0081] Further, according to the present embodiments, there are
explained the examples of the information communication section
that transmits a size of the CCD, the number of pixels of the CCD,
F-value of an image taking optical system, and a focal length on a
batch basis in form of the head parameters. However, any one is
acceptable, as the information transmission section referred to in
the present invention, which transmits at least one of a subject
distance up to the subject, a focal length of an image taking
optical system, a light-condensing ability, size and number of
pixels of the imaging device, and pixel pitch of the imaging
device.
[0082] Recently, there is developed a liquid lens in which a
voltage is applied to a liquid accommodated in a vessel to vary the
shape of a liquid surface so that a refractivity of a light is
controlled. According to the present embodiments, there is
explained the example in which the usual lens is used as the
imaging optical system referred to in the present invention.
However, it is acceptable that the imaging optical system referred
to in the present invention is a liquid lens. In this case, what is
meant by "drive of the imaging optical system" refers to a work for
applying a voltage to a liquid so as to perform working equivalent
to an effect that the usual lens is moved in the optical axis
direction.
[0083] As mentioned above, according to the present invention, it
is possible to implement a camera system comprising: a camera head
that is loaded with an image taking optical system for forming a
subject light and an imaging device that reads the subject light to
generate image data; and a camera main frame on which the camera
head is detachably mounted, wherein the camera system is capable of
computing the depth of field and the in-focus range, even if the
camera head is interchanged.
[0084] While the present invention has been described with
reference to the particular illustrative embodiments, it is not to
be restricted by those embodiments but only by the appended claims.
It is to be appreciated that those skilled in the art can change or
modify the embodiments without departing from the scope and sprit
of the present invention.
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